The use of prefabricated structural truss and joist assemblies has become increasingly widespread in recent years in view of the highly desirable load-bearing characteristics that can be achieved with the economy of mass production. Assemblies of this nature typically include a pair of spaced-apart truss chords between which extend a plurality of truss webs. So-called nail plate arrangements are frequently employed to provide connectors for joining the truss webs to the chords, with such arrangements including a multiplicity of teeth which are embedded in the wooden elements of the truss assembly. While the truss webs of the assembly may comprises wooden elements joined to the wooden chords with nail plates or other fastening means, the truss webs may further comprise suitably formed metallic material including integral nail plates. Depending upon the desired configuration of the truss assembly, both metallic and wooden truss webs may be employed.
Prefabrication of truss assemblies is effected with the use of jig-like forming machines. Devices of this nature are arranged to facilitate the desired relative positioning of the truss chords, webs, and nail plate connector portions. After the truss elements have been arranged in the desired configuraton, the elements are joined by firmly embedding the nail plate connector portions into the wooden elements of the assembly. While the connector portions may be manually hammered into place, suitable hydraulic clamps or pressure rollers are frequently used for efficient fabrication.
Since the configuration of a truss assembly is dictated by the requirements of the structure for which it is intended, a truss-forming apparatus which facilitates efficient formation of truss assemblies of varying dimensions and configurations is particularly desirable for lending efficiency to the truss-forming process, and avoids the need for different jig arrangements for forming different trusses. At the same time, it is very desirable that a forming apparatus be arranged to hold the elements of the truss in their proper closely-fitting relation during fabrication thereof to assure the intended structural integrity and load-bearing capabilities of the assembly. In keeping with these goals, the truss-forming apparatus of the present invention has been specifically configured for highly versatile use in efficiently forming truss assemblies of varying dimensions and configurations, and at the same time is arranged to position and maintain the elements of the truss in closely-fitting relation during its fabrication.